PATENT INFRINGEMENT SUIT FILED OVER SEROQUEL

AstraZeneca has initiated a patent infringement lawsuit challenging Teva Pharmaceutical's bid to launch a generic version of AstraZeneca's blockbuster schizophrenia treatment Seroquel (quetiapine fumarate).

UK-based AstraZeneca filed the lawsuit in the U.S. District Court for the District of New Jersey, alleging that Teva's abbreviated new drug application (ANDA) for quetiapine fumarate violates its substance patent protecting Seroquel. AstraZeneca's '288 patent on Seroquel isn't set to expire until 2011.

Financial analysts, including Merrill Lynch's Graham Perry, believe AstraZeneca holds a strong position. "Composition-of-matter patents are the strongest type and our initial assessment of the patent is that it is robust and likely to be successfully defended," Parry wrote in a recent research note. However, Teva could challenge the fact that the patent, originally scheduled to expire in 2007, was extended, he added.

Teva's ANDA, which was filed with the FDA in September, only challenges the 25-mg Seroquel dose, which accounts for 43 percent of the drug's total prescriptions. Seroquel is AstraZeneca's top-selling drug, generating worldwide sales of more than $2 billion in 2004.